The subject invention relates to word processing systems and, more particularly, to word processing systems having foreground and background modes of operation.
It is well known that the most modern and powerful word processing systems possess all the essential attributes of general purpose computers: memory, CPUs and I/O devices. Word processing systems differ only in that they are particularly adapted for text manipulation. Thus the most powerful word processors will include multiple line displays on which textual material being processed is displayed. Text is processed by specialized text manipulation functions in response to operator commands. Because text manipulation requires a large amount of operator intervention, and because word processing systems operate at rates many times faster than operators can input data through a keyboard, the utilization of word processing systems is very low. To increase utilization, it is known in the word processing art to operate word processing systems in what is known as foreground/background modes. That is, the word processing systems were programmed to performed two independent jobs concurrently. In the foreground, the operator would typically be performing text manipulation (i.e., inputting text, editing text, etc.). In the background, a second, independent job would run concurrently. The second job would typically be a job requiring little or no operator intervention, such as printing output or sorting data bases. In such prior art word processing systems, the background task's ability to interact with the operator was limited to simple clues such as flashing lights or brief status messages on a status line on the display. Because of the limited communication between the operator and the background task in previous word processing systems, only a small portion of the power of the word processing system was available for background tasks. In particular, tasks requiring extensive operator intervention, such as text insertion or editing, could not be run and background tasks were limited to tasks such as printing or records processing.
In the currently pending, commonly assigned U.S. patent application entitled CIRCUIT TO ENABLE FOREGROUND AND BACKGROUND PROCESSING IN A WORD PROCESSING SYSTEM WITH CIRCUIT FOR PERFORMING A PLURALITY OF INDEPENDENTLY CONTROL FUNCTIONS, Ser. No. 177,308, filed Aug. 12, 1980, which issued Aug. 9, 1983 as U.S. Pat. No. 4,398,264, a word processing system with foreground/background processing is taught. The word processing system of that invention has both a full page display and a keyboard with a single line display, and an illuminated key by means of which the operator may command the word processing system to switch between the foregound and the background. When the background task requires operator intervention, the system causes the illuminated key to flash. The operator may then switch to background and a message is shown on the one line display defining the required operator response. In principle, the system makes the full power of the word processing system available in the background mode. However, in practice, the lack of a multiline display for the background severally limits the ability of the operator to use the editing, and other text manipulation, capabilities of the word processing system in the background mode.
Thus, it is an object of the subject invention to provide a word processing system having foreground and background modes of operation wherein the full capabilities of the word processing may be used in the background mode.
In particular, it is an object of the subject invention to provide a word processing system wherein the operator may readily intervene in the background task with the full text manipulation capabilities of the word processing system available.
It is another object of the subject invention to provide a word processing system wherein the full display capabilities of the word processing system are available for the background task.